MODULE 3.1
Carbohydrates and Sugars and their MetabolismIn Chapter Two we learned that a cell is like a self-sustaining city, but that it
basically requires two outside factors. First, it needs an energy source. Just as
our car needs fuel, so do our cells. Secondly, they must be able to eliminate
the byproducts of these burned fuels. These by-products must be carried
away from the cells, much like the plumbing and septic systems work in your
house.
Carbohydrates refer to a group of chemical substances made up of
carbon, oxygen and hydrogen (carbon and water). They include starches,
sugars, glycogen, dextrins and celluloses. Carbohydrates are classified or
grouped by the number of carbon atoms they contain and by the
combinations of sugars. Since organic carbon compounds supply the main
energy source for cells, these carbohydrates are used by your body for its
primary energy supply.
All green plants use the sun’s energy (photosynthesis) to combine carbon
dioxide and water to form carbohydrates. Cellulose, the chief constituent of
the cell walls of plants, is a type of carbohydrate. When consumed by
humans, cellulose acts as an intestinal broom and energizer to the cells of the
intestinal walls.
SUGARS
A sugar is a carbohydrate belonging to the sac-charide family. Simple sugars
(also called monosaccarides) are the main fuels for your body. Sugars are as
essential to your body as gasoline is to your automobile. It helps run your
machine (your body) via the cells. However, there are several important
distinctions to understand about sugars.
Glucose (simple sugar) and its initial compounds, such as starch and
cellulose, make up the most abundant organic chemical compounds on earth.
Since your body can only use substances in their simplest forms, all complex
sugars (di- and polysaccharides) must first be broken down into simple
sugars (monosaccharides). This is one aspect of the process of digestion.